The Collaborative International Dictionary of English v.0.48:

meperidine \meperidine\ n.
   A synthetic narcotic drug used as a sedative; Demerol is
   the trademark of a brand of meperidine.

   Syn: meperidine hydrochloride, Demerol.
        [WordNet 1.5] Mephistophelean

WordNet (r) 3.0 (2006):

Demerol
    n 1: a synthetic narcotic drug (trade name Demerol) used to
         treat pain [syn: meperidine, meperidine hydrochloride,
         Demerol]

Moby Thesaurus II by Grady Ward, 1.0:

83 Moby Thesaurus words for "Demerol":
   Amytal, Amytal pill, Dolophine, H, Luminal, Luminal pill, M,
   Mickey Finn, Nembutal, Nembutal pill, Seconal, Seconal pill,
   Tuinal, Tuinal pill, alcohol, amobarbital sodium, analgesic,
   anodyne, barb, barbiturate, barbiturate pill, black stuff, blue,
   blue angel, blue devil, blue heaven, blue velvet, calmative,
   chloral hydrate, codeine, codeine cough syrup, depressant,
   depressor, dolly, downer, goofball, hard stuff, heroin, hop, horse,
   hypnotic, junk, knockout drops, laudanum, liquor, lotus,
   meperidine, methadone, morphia, morphine, narcotic, opiate, opium,
   pacifier, pain killer, paregoric, pen yan, phenobarbital,
   phenobarbital sodium, purple heart, quietener, rainbow, red, scag,
   secobarbital sodium, sedative, shit, sleep-inducer, sleeper,
   sleeping draught, sleeping pill, smack, sodium thiopental,
   somnifacient, soother, soothing syrup, soporific, tar,
   tranquilizer, turps, white stuff, yellow, yellow jacket